One traditional vacuum cleaner is arranged with a filter device for filtering suctioned dust-laden air, and leaving dust particles in a dust collecting device, so that the filter device should be cleaned or replaced after used for a period of time, otherwise, fine dust may clog filter holes of the filter device, which will increase resistance of the dedust motor, even burn the motor out, thereby not only bringing trouble for users, but also adversely affecting performance and life-span of the vacuum cleaner.
In recent years, a cyclonic dedusting device is widely used in vacuum cleaner instead of the filter device by manufacturers according to the principle of cyclone separation, which has obtained a relatively fine dedusting effect. The cyclonic dedusting device mounts a conical barrel with a large upper end and a relatively small lower end in the dust cup, a wind outlet tube is vertically disposed at the upper end of the conical barrel, the lower end of the conical barrel is opened so as to allow dust to drop into the bottom of the dust cup, a wind inlet tube enters into a side wall of an upper portion of the conical barrel along a tangent direction, so that the dust-laden air flow entering the conical barrel through the wind inlet tube produces cyclone and the dust particles drop into a bottom of a dust collecting barrel along the side wall of the conical barrel due to centrifugal force caused by cyclonic air flow, finally only dust-free air flow is upwardly discharged into the atmosphere through the wind outlet tube.
However, the cyclonic dedusting device has a relatively large bulk, especially a cyclonic dedusting device used for a large vacuum cleaner requiring a relatively large air flow has a larger bulk, which not only increases manufacturing cost thereof, but also brings much inconvenience for users.